Adobe Dreamweaver CC 2015 - Manual (Page 608)

601
Dynamic sites, pages and web forms
Last updated 6/3/2015
The loop directive includes two built-in variables that you can use for embedded if conditions. The variables are:
_length and _index. The _length variable evaluates to the length of the arrays processed by the loop directive, while the
_index variable evaluates to the current index of the loop directive. To ensure that the variables are only recognized as
directives, and not as actual parameters to be passed into the loop, do not enclose either variable in @@s.
An example of using built-in variables is to apply them to the import attribute of the page directive. The import attribute
requires comma separation of packages. If the loop directive extends around the entire import attribute, you would only
output the attribute name import= on the first iteration of the loop—this includes the closing double quote (")—and
not output a comma on the last iteration of the loop. Using the built-in variable, you can express this as follows:
<@loop (@@Import@@)@>
<@ if(_index == 0)@>import="
<@endif@>@@Import@@<@if (_index == _length-1)@>"<@else@>,
<@ endif @>
<@endloop@>
Request a parameter for the server behavior
Server behaviors often require that the page designer supply a parameter value. This value must be inserted before the
server behavior’s code is inserted into the page.
You create the dialog box by defining the designer-supplied parameters in the code. Then you generate a dialog box for
the server behavior, which prompts the page designer for a parameter value.
Note: A parameter is added to your code block without your intervention if you specify that your code should be inserted
relative to a specific tag chosen by the page designer (that is, you chose Relative to a Specific Tag in the Insert Code pop-up
menu). The parameter adds a tag menu to the behavior’s dialog box to let the page designer select a tag.
Define the parameter in the server behavior code
1 Enter a parameter marker in the code where you want to insert the supplied parameter value. The parameter has the
following syntax:
@@parameterName@@
2 Enclose the formParam string in parameter markers (@@):
<% Session(“lang_pref”) = Request.Form(“@@formParam@@”); %>
For example, if the server behavior contains the following code block:
<% Session(“lang_pref”) = Request.Form(“Form_Object_Name”); %>
To require the page designer to supply the value of Form_Object_Name, enclose the string in parameter markers
(@@):<% Session(“lang_pref ”) = Request.Form(“@@Form_Object_Name@@”); %>
<% Session(“lang_pref”) = Request.Form(“@@Form_Object_Name@@”); %>
You can also highlight the string and click the Insert Parameter In Code Block button. Enter a parameter name and
click OK. Dreamweaver replaces every instance of the highlighted string with the specified parameter name enclosed
in parameter markers.
Dreamweaver uses the strings that you enclose in parameter markers to label the controls in the dialog box it generates
(see the following procedure). In the previous example, Dreamweaver creates a dialog box with the following label:
Note: Parameter names in the server behavior code cannot have any spaces. Therefore, the dialog box labels cannot have
any spaces. If you want to include spaces in the label, you can edit the generated HTML file.